Particulate air pollution and daily mortality on Utah's Wasatch Front

Area of Science:

• Environmental epidemiology
• Air pollution and public health

Background:

• Daily mortality is associated with short-term changes in particulate matter (PM) air pollution globally.
• Salt Lake City, Utah, showed weaker PM-mortality associations compared to nearby Provo/Orem, Utah.

Purpose of the Study:

• To investigate the discrepancy in PM-mortality associations between Salt Lake City and Provo/Orem.
• To analyze mortality, pollution, and weather data for Ogden, Salt Lake City, and Provo/Orem, Utah (1985-1995).

Main Methods:

• Utilized generalized additive Poisson regression models.
• Controlled for seasonality, temperature, humidity, and barometric pressure.
• Screened data to exclude windblown dust episodes and used mean PM10 exposure estimates.

Main Results:

• Salt Lake City experienced more high PM episodes dominated by windblown dust.
• After screening and using mean PM10 data, comparable PM-mortality effects were observed across the three areas.
• Estimated percent change in mortality for a 10-mg/m3 increase in PM10: Ogden 1.6%, Salt Lake City 0.8%, Provo/Orem 1.0%.

Conclusions:

• Stagnant air pollution episodes with combustion particles were more strongly associated with elevated mortality.
• Windblown dust episodes, with coarse crustal particles, showed weaker mortality associations.
• The type of PM, not just concentration, influences mortality effects.